(A) Field of the Invention
The present invention generally relates to a user interface display apparatus. More particular, the invention relates to a low cost user interface (UI) display apparatus, like on screen display (OSD) in TV, video player, projector, monitor, or display panel of telephone, consumer household appliances, electronic dictionary, calculator, electronic caption, clock, bulletin board, or pager. OSD means a display function which shows the message on screen for user to select or change some functions of application system. Normally it is overlap on the display window.
(B) Description of the Related Art
In the art, a display system with a low cost user interface (UI) display apparatus means a display system without powerful Central Processing Unit (CPU) and Operation System (OS) for display function, and just display the message for user to select or change which built-in function in device will be used, like used OSD in TV, computer monitor, video player, or display panel of telephone, consumer household appliances, electronic dictionary, calculator, or simply display the message for user to watch, like used in a electronic caption, clock, watch, bulletin board, and pager.
The UI display in these systems is not the major function, but just provides an interface for user to adjust some functions of the system. The CPU in these systems is just fit for the major function, and no extra power for fancy display. So the UI display is usually as simple as possible and the cost of UI display apparatus is lower than the major display function device.
Nowadays, the color display device like LCD will be widely used to replace many kinds of display device, but the UI display function is still simple. Compared to the powerful display ability of computer with GUI (graphic user interface) like Microsoft Windows, the UI of low cost display devices are still with a very simple form. For example, the OSD function on PC's monitor is simple, and with limited color compared to the PC versatile window operation system. That's due to the OSD function is performed in the monitor side but not in the PC side.
Two methods were provided to perform the OSD function for UI display in the prior art.
FIG. 1 shows UI display using a character base method. This method divides the UI display range to pieces of characters, each character 102 is predefined. A display code-buffer is used to arrange the character for display and store the character index of character set 103 for display window. For example, if a UI display window with size 128×60 dots, and each character 102 is 16×12 dots, thus the UI display window can be divided into 8×5 characters, and the size of display code-buffer 100 is 8×5×CW (“CW” is the code index width). Dmn 101 means at the matrix location (m,n) where is the display code-buffer 100 store the code for addressing the content in character set 102. A character set 103 with 256 character counts will have 8 bits CW (28=256). By the way, each character 102 color depth (D) also could be defined, typically, as 1 bit, 2 bits, 3 bits, or 4 bits. 1 bit means 2 colors, 2 bits means 4 colors and so on.
In this case, the required space of a memory to store a character 102 is 16×12×D. The memory cost will depend on quantity of character font, character size, and color depth D. For some display patterns need the same text, like character “A”, we can use the same character font by setting the code-buffer index to reduce the memory usage. That's the main advantage of character base UI.
FIG. 2 shows the UI using bitmap method. Bitmap method is a simple way to display all kinds of needed patterns. By predefined all kinds of patterns stored in memory bank 201, the display choose which pattern is need for current UI display 202. The pattern 200 is the one of the image stored in the memory bank 201 and will be displayed next time on UI display 202. The memory usage is huge since all patterns during user operation must be prepared and hard to be reuse. It does not take the advantage of character base method, so one pattern may need the size equal to one UI display range. The memory storage requirement is typically P times the display window sizes. P is the pattern counts of UI function, and the display window sizes depends on H×V×D, H is the horizontal size, V is the vertical size, and D is the color depth per dot.
Above two methods still limited to the memory cost, and make the fancy UI hard to implement. The present invention can make the UI display much fancy with a little texture memory added. It is the simplest way for UI designer to design a fancy UI display, and make it easy to accept by end-user. Using texture mapping method can be very easy to fancy character base UI display by only adding a little texture memory. The total memory required for one character set is 16×12×D×(number of character font), where the character size is set as 16×12 dots and D colors.